He puts it all out simple and plain, with neither alarming nor solace. For example, he writes "The outlook may be for increased crop productivity overall, with increases in the north exceeding the reductions over the equator. Global warming may not decrease overall food supply, but it may give more to the rich and less to the poor."
He notes that in the northern midlatitudes (30°N to 60°N), the annual average temperature drops about 2/3rds of a degree C with each degree of increasing latitude.
"With five degrees of warming in a century, that translates into an average poleward movement of more than 800 kilometers in that period, for an average poleward movement of temperature bands exceeding 20 meters each day. Squirrels may be able to keep up with this rate, but oak trees and earthworms have difficulty moving that fast."Over the last 20 years, GISS's northern hemisphere temperature has increased at a rate of 0.27°C/decade. Let's exclude the equatorial region and call it 0.2°C/decade. That implies a current rate of climate shift of over one foot each hour. Over 6 millimeters a minute. 2.1 miles a year.
You should read his article, even if you have to buy the issue, a special one themed "Beyond the Limits of Science," for your tablet or off the newstand.